Protesters clash with National Guard troops in Los Angeles – What do we know?

Tensions in Los Angeles (LA) escalated on Sunday as thousands of protesters took to the streets in response to U.S. President Donald Trump's extraordinary deployment of the National Guard, blocking off a major freeway and setting self-driving cars on fire as law enforcement used tear gas, rubber bullets, and flash bangs to control the crowd.

Some police patrolled the streets on horseback, while others with riot gear lined up behind Guard troops deployed to protect federal facilities including a detention center where some immigrants were taken in recently. Police declared an unlawful assembly, and by early evening many people had left.

However, protesters who remained grabbed chairs from a nearby public park to form a makeshift barrier, throwing objects at police. Others standing above the closed southbound 101 Freeway threw chunks of concrete, rocks, electric scooters and fireworks at California Highway Patrol officers and their vehicles that were parked on the highway. Officers took cover under an overpass.

It was the third day of demonstrations against U.S. President Donald Trump's immigration crackdown in the region, as the arrival of around 300 federal troops spurred anger and fear among some residents. Sunday's protests in Los Angeles, a city of 4 million people, were centered in several downtown blocks.

Starting in the morning, National Guard troops stood shoulder to shoulder, carrying long guns and riot shields outside the Metropolitan Detention Center in downtown Los Angeles. Protesters shouted "shame" and "go home." After some approached the troops, another set of uniformed officers advanced on the group, shooting smoke-filled canisters into the street.

Minutes later, the Los Angeles Police Department fired rounds of crowd-control munitions to disperse the protesters, who they said were assembled unlawfully. Much of the group then moved to block traffic on the 101 freeway until state patrol officers cleared them from the roadway late afternoon, while southbound lanes remained shut down.

Nearby, at least four self-driving Waymo cars were set on fire, sending large plumes of black smoke into the sky and exploding intermittently as the electric vehicles burned. By evening, police had issued an unlawful assembly order shutting down several blocks of downtown Los Angeles.

California Governor Gavin Newsom requested Trump remove the guard members in a letter Sunday afternoon, calling their deployment a "serious breach of state sovereignty." He was in Los Angeles meeting with local law enforcement and officials. It wasn't clear if he'd spoken to Trump since Friday.

Their deployment appeared to be the first time in decades that a state's national guard was activated without a request from its governor, a significant escalation against those who have sought to hinder the administration's mass deportation efforts.

Deployment follows days of protest

The arrival of the National Guard followed two days of protests that began on Friday in downtown Los Angeles before spreading on Saturday to Paramount, a heavily Latino dominant city south of the California, and neighboring Compton.

Federal agents arrested immigrants in LA's fashion district, in a Home Depot parking lot and at several other locations on Friday. The next day, they were staging at a Department of Homeland Security office near another Home Depot in Paramount, which drew out protesters who suspected another raid. Federal authorities later said there was no enforcement activity at that Home Depot.

Demonstrators attempted to block Border Patrol vehicles by hurling rocks and chunks of cement. In response, agents in riot gear unleashed tear gas, flash-bang explosives and pepper balls.

The weeklong tally of immigrant arrests in the LA area climbed above 100, federal authorities said. Many more were arrested while protesting, including a prominent union leader who was accused of impeding law enforcement.

The last time the National Guard was activated without a governor's permission was in 1965, when President Lyndon B. Johnson sent troops to protect a civil rights march in Alabama, according to the Brennan Center for Justice.

Trump told reporters as he prepared to board Air Force One in Morristown, New Jersey, Sunday that there were "violent people" in Los Angeles "and they're not gonna get away with it."

(With input from agencies)